[sles-beta] A Problem with KVM Guest ?

[Günther J. Niederwimmer]

Am Donnerstag, 4. September 2014, 16:47:23 schrieb Antoine Ginies:
> Günther J. Niederwimmer:
> > Hello Antoine,
> > 
> > Am Donnerstag, 4. September 2014, 16:23:29 schrieb Antoine Ginies:
> > > Günther J. Niederwimmer:
> > > > Am Donnerstag, 4. September 2014, 13:57:01 schrieb Antoine Ginies:
> > > > > Günther J. Niederwimmer:
> > > > > > Am Donnerstag, 4. September 2014, 12:24:02 schrieb Antoine Ginies:
> > > > > > > Günther J. Niederwimmer:
> > > > > > > > Hello,
> > > > > > > > I found a Problem with KVM_clock?
> > > > > > > > on my Installation I have a KVM Server and KVM Clients all
> > > > > > > > SLES 12
> > > > > > > > Server
> > > > > > > > The KVM Host have a NTP Server configured and have a correct
> > > > > > > > time
> > > > > > > > 
> > > > > > > > date
> > > > > > > > Don Sep  4 12:00:19 CEST 2014
> > > > > > > > all clients have this Time
> > > > > > > > date
> > > > > > > > Don Sep  4 02:15:24 CEST 2014
> > > > > > > > 
> > > > > > > > the timezone is correct but the time is wrong ?
> > > > > > > 
> > > > > > > Hello,
> > > > > > > Can you check that your VM is currently using kvm_clock?
> > > > > > 
> > > > > > akerb:~ # dmesg | grep kvm-clock
> > > > > > [    0.000000] kvm-clock: Using msrs 4b564d01 and 4b564d00
> > > > > > [    0.000000] kvm-clock: cpu 0, msr 1:3ff18001, boot clock
> > > > > > [    0.000000] kvm-clock: cpu 0, msr 1:3ff18001, primary cpu clock
> > > > > > [    0.004000] kvm-clock: cpu 1, msr 1:3ff18041, secondary cpu
> > > > > > clock
> > > > > > [    0.004000] kvm-clock: cpu 2, msr 1:3ff18081, secondary cpu
> > > > > > clock
> > > > > > [    0.004000] kvm-clock: cpu 3, msr 1:3ff180c1, secondary cpu
> > > > > > clock
> > > > > > [    0.134685] Switched to clocksource kvm-clock
> > > > > > 
> > > > > > This is the client
> > > > > > 
> > > > > > root# cat
> > > > > > /sys/devices/system/clocksource/clocksource0/current_clocksource
> > > > > 
> > > > > You forget the value, but according to dmesg it was kvm-clock at
> > > > > 0.134685 until something else has switched to another value.
> > > > 
> > > > I mean we miss understand  use
> > > > 
> > > > The behind is from a CLIENT
> > > 
> > > kvm-clock clocksource is for the VM guest.
> > > 
> > > > This is from the HOST !!
> > > 
> > > The host doesn't provide kvm-clock source:
> > > -----------------------------------------
> > > root # cat
> > > /sys/devices/system/clocksource/clocksource0/available_clocksource tsc
> > > hpet
> > > acpi_pm
> > > -----------------------------------------
> > > 
> > > It's tsc by default.
> > > So everything is ok.
> > :
> > :-))).
> > 
> > why I have then a wrong Time !
> 
> Perhaps the ntpd service was not started on the host before the VM guest
> start? have you tried to start the ntpd server on the host, then
> start a VM guest and check if time are synchronized?

Yes, you are right, this is the Problem, NTP Server is starting to late for 
the VM clients

always this Problems with systemd :-(.

Now I have to check what can I do, a kerberos test in the moment is not the 
best Timing ;-)

Thanks, I hope you find a way to clear this Problem.

Thanks again. 
 
> > anything must be wrong, the question is what?
> > 
> > > >  dmesg | grep clocksource
> > > > 
> > > > [    0.560063] Switched to clocksource hpet
> > > > [    2.329666] tsc: Refined TSC clocksource calibration: 3700.000 MHz
> > > > [    3.645349] Switched to clocksource tsc
> > > > 
> > > > and I like to change this for Tests.
> > > > 
> > > > > ------------
> > > > > root # dmesg | grep clocksource
> > > > > ------------
> > > > > will let you know if there is any change.
> > > > > 
> > > > > > I have on the Server
> > > > > > tsc
> > > > > > 
> > > > > > This is a original YaSt Installation
> > > > > > 
> > > > > > can I change this manual ?
> > > > > 
> > > > > On VM guest you can change it with echo:
> > > > > ----------
> > > > > echo tsc >
> > > > > /sys/devices/system/clocksource/clocksource0/current_clocksource
> > > > > echo kvm-clock >
> > > > > /sys/devices/system/clocksource/clocksource0/current_clocksource
> > > > > ----------
> > > > > 
> > > > > You should see a dmesg in the console of your VM guest saying that
> > > > > clocksource has switched.
> > > > 
> > > > Have I to open a SR ?

-- 
mit freundlichen Grüßen / best Regards,

  Günther J. Niederwimmer